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Öğe Adaptation of Oil Cooled Condenser Design to A Thermostat Controlled Cooler and Performance Analysis(Gazi Univ, 2019) Acar, BahadirToday, the need for cooling and cooling technologies are growing fast and they are used in many areas. On the other hand, saving energy and using the cooling systems more efficiently are major concerns in today's growing energy needs. Increasing the condenser capacity is one of the way of improving household refrigerator efficiency. In this study, first the performance test of a natural circulation wire-tube condenser was tested. Then the condenser was placed into a tank and 2.5, 5, 7.5 and 10 liters of melted vegetable oil was filled into the tank. Performance tests of the system were performed at both loaded and unloaded conditions as intermittent operation. A domestic refrigerator was run for 2 hours as intermittent operation for each scenario. All measurements (pressure and temperature) were taken at 5 minutes intervals. Experimental results showed that as the amount of oil in the oil-cooled condenser increases, the condenser capacity and cooling capacity also increase, and also the energy consumption of the system decreases. The energy consumption in unloaded operation of air-cooled condenser for 1 hour was measured as 90 Wh, and it decreased to 35 Wh for oil-cooled condenser filled with 10 liters of oil. The COP of the system in unloaded operation of air-cooled condenser was calculated as 2.23 and the energy consumption was about 90Wh. However, The COP of the system in loaded operation of oil-cooled condenser was increased to 2.81 and the energy consumption was decreased to 35Wh. On the other hand, the COP of the system in loaded operation of air-cooled condenser was measured as 2.14 and the energy consumption of it was about 95Wh. But, the COP of the oil-cooled condenser in loaded operation raised to 2.84 and the energy consumption reduced to 40Wh.Öğe Design of Hazelnut Drying System Supported By Solar Energy, Investigation of Drying Performance and Determination of Proper Drying Model(Int Journal Renewable Energy Research, 2020) Acar, Bahadir; Dagdeviren, Abdullah; Ozkaymak, MehmetRapid and efficient drying process for the hazelnuts is required because of the lack of plain areas for solar drying due to the rough landforms in the Black Sea Region, high amount of cloudy days, causing product deteriorations and rots by instantaneous rain transitions and unexpected sudden rains. In this study, a hazelnut drying system supported by solar energy in order to achieve a rapid and efficient drying process was designed and drying performance was examined. In the designed system, a spiral shaft was used for movements of the hazelnuts in the drying chamber. Besides, the inner temperature of the chamber increased with the help of a sun collector. The process control device was used to keep the inner temperature as constant at 40 degrees C. In the experiments, 20kg weight hazelnut husk was used. The experiment was performed between 09:00 and 17:00 hours in a day with normal sunlight conditions and the total drying process took about 8 hours. The moisture ratios (MR) and drying rates (DR) graphics were obtained by scaling weight losses of the hazelnuts in each hour. As a result, it is observed that the 20kg weight of the hazelnuts decreased to the 17.201kg and therewith the total removed moisture from the hazelnuts was about 2.799kg. In the light of the moisture ratios obtained by experiments, 8 different kinetic drying models were performed with MATLAB software. According to the kinetic model results, the lowest reduced chi-square (chi(2)) and root mean square error (RMSE) were about 241x10(-6) and 155x10(-4) respectively. In addition, the coefficient of determination (R-2) was calculated as 0.9982 which is the highest result closest to 1. Among the 8 kinetic models, the Page model is given the best results for the drying process.Öğe Determination freeze-drying characteristics of ottoman strawberries(Gazi Univ, 2023) Acar, Bahadir; Dagdeviren, Abdullah; Yildiz, Busra Meryem; Ozkaymak, MehmetThis study was performed to define the kinetic drying model and to define the effective diffusivity coefficient of the fruit, which is called ottoman strawberries in the literature. In the study, strawberries by the weight of 100 g and with a thickness of 5 mm were placed in the drying device, and the data were processed by observing the weight loss every two hours after being subjected to the drying process for 14 hours. 8 different kinetic drying models were applied to the acquired data using the MATLAB program. As a result of the application, the estimated standard errors (RMSE), chi-square (X2), regression coefficients (R2) were calculated, error analysis was performed, R2, X2, and RMSE values were found, as 9,998x10-1, 6,993x10-5 and 0.7242x10-2. According to these results, the model of strawberry was determined that the most suitable model is the Page model. Also, the effective diffusivity coefficients for ottoman strawberries were calculated as 2.73286 x 10-10 m2/s. It was confirmed that the calculated effective diffusivity value was within the reference range mentioned in the literature (10-12 m2/s - 10-8 m2/s) for food products.Öğe Determination of the heat transfer coefficient of PV panels(Pergamon-Elsevier Science Ltd, 2019) Ceylan, Ilhan; Yilmaz, Sezayi; Inanc, Ozgur; Ergun, Alper; Gurel, Ali Etem; Acar, Bahadir; Aksu, Ali IlkerIn this study, the efficiency of the rear-panel air velocity in cooling was investigated based on the temperature and solar radiation in the environment where the panels are located. During the cooling of the panels, the rear-panel temperature decreases, and accordingly, the open-circuit voltage of the panels increases. At present, the most important losses in panels are due to the increase in panel temperature depending on the solar radiation and outdoor air temperature. In this study, the rear-panel temperature changes were observed at 0-5 m/s air velocities and 10-40 degrees C. The calculations reveal that in winter weather conditions, the temperature of the panels did not increase at a level that would require cooling. This study investigated the heat transfer from the surface depending on the outdoor air temperature of the rear-panel air velocity and the changing rear-panel temperature. The effect of different outdoor air temperatures on the rear-panel heat transfer is minimal. When the air velocity was 5 m/s and the outdoor air temperature was 10-40 degrees C, the heat transfer in the Poly Crystal Solar panel was calculated as 11.6 W/m(2)K. (C) 2019 Elsevier Ltd. All rights reserved.Öğe Drying of Kanlıca Mushroom by the Hot Air Drying Method and the Investigations of Its Effects on Its Quality(Gazi Univ, 2023) Ongun, Goknur Kayatas; Aktas, Mustafa; Acar, Bahadir; Ozkaymak, MehmetIn this study, by providing the hot air drying of Kanlica mushroom collected from Karabuk city; prevention of aflatoxin occurrence, shelf life extension, taking precaution against early putrefaction and decomposition, protection of the beneficent aromas in its content have been ensured. As the dried product, Kanlica mushroom, the most consumed endemic plant spicy in terms of the vitamin and the mineral that it contains among the mushroom groups, has been used. By means of hot air drying, drying has been done at five different (30 oC, 40 oC, 50 oC, 60 oC and 70 oC) temperatures. The best result in terms of water activity, colour changes, energy consumption and drying duration has been obtained in the experiments at 50 oC. The water activity values of products (fresh mushroom water activity: 0,983 aw) dried in hot air drying processes have been found in 0,429 and 0,173 interval (in literature lower than 0,6) and according to the colour analysis experiments result, L*, a*, b*, C*, Ho, increment E, BI values of Kanlica mushroom dried at different temperatures have been calculated. According to the result of the analyses, it has been detected that the preservation of mushrooms hot air drying is appropriate.Öğe Economical Analysis of Huawei MA5622 External Active Access Device Charged by Photovoltaic Panel(Int Journal Renewable Energy Research, 2020) Acar, Bahadir; Bas, Sahin; Yiliz, OzlemIn the communication sector, in order to provide broadband internet and fixed telephone services to customers, systems called external active access devices are installed inside the building. These devices, which are usually installed in buildings in the city centers, are supplied by energy from city grid. In this study, economic analysis of HUAWEI MA5622 external active access device have been explored which is installed in 185 buildings in Karabuk province is provided by grid connected solar energy system. Karabuk province has been taken as a role model for the other regional applications that would be applied later, and after this stage it will be called as pilot province. First of all, 300 Wp installed solar power system was designed to meet the greatest amount of energy needs of system and to meet the missing energy requirements from grid. In this way, minimum material cost and depreciation period at low installed power were calculated. Afterwards, beyond the entire power demand of the system was met, the excess power produced was planned to be sold to rid and installed power was increased. In this way, 5 different installed power system design in 600Wp, 1.5kWp, 3kWp, 5kWp, 10kWp was also made by calculating depreciation period for each system designed. The design and simulations of solar energy systems were realized by program named as PVSYST. According to the data obtained from the simulation results, the depreciation periods of the systems designed with 300Wp, 600Wp, 1.5Wp, 3kWp, 5kWp, 10kWp installed power are calculated respectively 37.8 years, 22.1 years, 16.3 years, 13.1 years, 12.2 and 9.9 years. As a result, it has been seen that depreciation period decreases as the installed power increases and the most economical system design is found to be 10kWp installed power system.Öğe Energy-exergy-ANN analyses of solar-assisted fluidized bed dryer(Taylor & Francis Inc, 2017) Ergun, Alper; Ceylan, Ilhan; Acar, Bahadir; Erkaymaz, HandeIn this study, a temperature-controlled solar air collector was designed and tested for drying. Solar drying systems have two disadvantages. First one is the lack of ability to store energy and the second one is the lack of temperature control. This study presents the experimental analysis of an air collector that is able to keep the drying air temperature at 40 degrees C even in cases where the level of solar radiation received by the collectors changes. Most of the tests were performed at a solar radiation level ranging from 500 to 900W/m(2) and at an air flow of 3 to 5m/s. The system tested for drying three different crops separately performed 21h of a total of 27-h drying period at or above the temperature set of 40 degrees C. The thermodynamic analysis of the relationship between solar radiation, air temperature, flow, and the produced energy was performed. The relationship between productivity, energy produced, and set temperature was analyzed using distribution charts. Moreover, an artificial neural network model was used to estimate outlet air temperature from the solar collectors based on air flow, solar radiation, and outside air temperature.Öğe Experimental Investigation of a Household Refrigerator Performance Using Chimney-Type Condenser(Springer Heidelberg, 2016) Gedik, Engin; Kilicaslan, Erdogan; Acar, Bahadir; Ergun, Alper; Ozbas, EnginIn this study, the condenser unit was investigated experimentally in order to search for the effect of using chimney on the performance of a household refrigerator charged with 139 g of R134a refrigerant. An experimental design based on chimney-type condenser has been developed, and three chimneys having different size were produced. A series of measurements were conducted over the climatic conditions of Karabuk/Turkey, and results show that the efficiency and energy consumption of the refrigerator vary with the chimney height. Results showed that the best performance observed was for the 170cm chimney height. Energy consumption of natural convection with chimney was found less than that of natural convection by 5 and 10% for the loaded and unloaded situations of the refrigerator.Öğe EXPERIMENTAL INVESTIGATION OF COLLECTOR EFFICIENCIES ON SEPARATED AND CONNECTED HEAT PIPES(Gazi Univ, Fac Engineering Architecture, 2008) Acar, Bahadir; Oz, Etem Sait; Gedik, EnginThe aim of study is to determine the effect of heat pipe systems to collector efficiency at solar collectors used in supplying hot water. For this purpose, two different collectors as the connected heat pipe and separated heat pipe have been produced. The experimental studies with the collectors have been conducted in Karabuk city environment. The experiments have been completed in six days. The collector efficiencies have been calculated by measuring temperature of water tanks, ambient temperature and solar radiation in both collectors. As a result, while average efficiency of the connected heat pipe collector is 57.6%, average efficiency of the separated heat pipe collector is 48.5%Öğe Experimental Investigation of Freeze-Dried of Kanlica Mushroom (Lactarius Salmoncolor)(Gazi Univ, 2023) Ongun, Goknur Kayatas; Ozkaymak, Mehmet; Acar, Bahadir; Aktas, Mustafa; Dagdeviren, AbdullahIn this study, it is examined to prevent the formation of toxins by providing drying of the kanlica mushroom, which is unique to Karabuk, by freezing, to extend the shelf life, to take measures against early decay and spoilage. As the dried product, kanlica mushroom, which is an endemic plant, contains high amounts of protein and amino acids. In this study, the 5 mm thick cut kanlica mushroom was placed in a freeze-drying device and the drying process was initiated. Weight losses during drying were recorded and kinetic models were created. In the experiment lasting 14 hours in total, 100 gr. The weights of the canlica mushrooms were measured every two hours and MR (Moisture rates) were calculated. According to our results, the lowest chi-square (X-2) was 1.851 x10(-4) and the estimated standard error (RMSE) value was 0.01358. The correlation value (R-2) was calculated as 0.9988, close to one. The best Page model gave these results from the kinetic models. The effective diffusivity for the Kanlica Mushroom with 5 mm thicknesses can be calculated at about 3.2035x10(-10) m(2)/s. It was confirmed that the calculated effective diffusivity value was within the reference range mentioned in the literature (10(-12) m(2)/s - 10(-8) m(2)/s) for food products.Öğe EXPERIMENTAL INVESTIGATION ON THE EFFECT OF SOIL TYPE TO THE GROUND SOURCE HEAT PUMP'S PERFORMANCE AND ENERGY CONSUMPTION(Vinca Inst Nuclear Sci, 2020) Acar, BahadirIn the present study an experimental investigation is carried out to predict the performance of ground source heat pump systems with using different soil type under Karabuk prevailing conditions. A series of experiments were conducted on designed and produced experimental test rig. This study examines the effect of five different soil types on the performance and energy consumption of a heat pump. The experimental analysis showed that the evaporator capacity provided by sand was 46% and 42% higher than the capacity provided by red soil at the air-flow rates of 0.087 kg/s and 0.015 kg/s, respectively. In terms of the condenser capacity, sand provided 46% and 30% higher capacity than red soil at the air-flow rates o 0.087 kg/s and 0.015 kg/s, respectively. On the other hand, red soil consumed 8% and 6% less energy than sand at the air-flow rates of 0.087 kg/s and 0.015 kg/s. the capacities provided by other soil types and their energy consumption ranged between these values. In terms of the COP values, red soil provided 6% higher performance than sand and humus soil at the air-flow rates of 0.087 kg/s and 0.015 kg/s. The performance values obtained with other soil types ranged between these values.Öğe Freeze Drying of Saffron (Crocus sativus L.)(Taylor & Francis Inc, 2011) Acar, Bahadir; Sadikoglu, Hasan; Ozkaymak, MehmetSaffron obtained from the dried stigmas of a flower scientifically known as Crocus sativus L. is considered to be the most precious and expensive agricultural product due to its labor-intensive harvest and post-harvest processing. The post-harvest processing such as dehydration and storage conditions determine stability, quality, and economical value of the final product. The contents of crocin (degraded carotenoids) and safranal (carotenoid oxidation products) are the key components that characterize color, taste, and aroma characteristics of saffron. In this work, the quality parameters such as crocin and safranal contents of commercial saffron that were obtained by using the freeze-drying method and natural sun drying were studied. The sarfanal contents of the samples dried in a freeze dryer were found to be five times higher than the safranal contents of the samples dried naturally under the sun, while crocin contents of the samples dried in a freeze dryer were about 40% higher than the crocin contents of the samples dried naturally under the sun. These encouraging results indicate that the freeze-drying process can be used effectively for dehydration of saffron by minimal loss of safranal and crocin contents.Öğe Freeze Drying Process of Kiwi Slices with Various Thicknesses and Investigation Drying Characteristic of Process(Gazi Univ, 2023) Acar, Bahadir; Dagdeviren, Abdullah; Ozkaymak, Mehmet; Guinaleh, Abdillahi RoblehIn the study, the kiwi fruit was sliced into various thicknesses as 5 mm and 7 mm, and those sliced specimens were put in the freeze-drying device. the mass losses of the specimens were measured and saved during the drying process and kinetic drying models were performed using those measurements. The mass losses of each kiwi slices in 100 g mass were measured every two hours in the experiment lasting 14 hours in total and moisture ratios (MR) were calculated as well. Considering the experimental results, 8 different kinetics drying models were performed using MATLAB software. As a result, the lowest reduced chi-square (X-2) values for 5 mm and 7 mm thicknesses were calculated about 8.261x10(-6) and 1.705x10(-5) respectively, the root means square error values (RMSE) were about 0.002865 and 0.004146, respectively. Also, the coefficient of determination (R-2) for both thicknesses was calculated as 0.9999 which was the highest result closest to 1. Among the 8 different kinetic drying models, the Logarithmic model was chosen as a proper kinetic drying model for kiwi products. When the moisture contents and drying rates were considered it was seen that the drying rate of kiwi slices with 7 mm thickness exhibited slow behavior because of the higher moisture content. Besides, it was determined that the effective diffusivity coefficients for specimens with 5 mm and 7 mm thickness were calculated as 2.25 x 10(-10) m(2)/s and 3.28 x 10(-10) m(2)/s respectively.Öğe Freeze-drying kinetics and diffusion modeling of hawthorn(Yildiz Technical Univ, 2023) Hagig, Khaled Ali; Acar, Bahadir; Dagdeviren, Abdullah; Taskesen, Edip; Ozkaymak, MehmetThis study tests freeze-drying (FD) technology (Scanvac Coolsafe model, Labogene brand) to preserve hawthorn fruit. First, 100g hawthorn slices were frozen and then freeze-dried. Kinetic models were applied, and hawthorn's moisture ratio and weight loss were noted after every two hours during the 14-hour freeze-drying process. Matlab program is used to perform a total of eight kinetic drying models. Results show that the root mean square error was 0.011063, the highest determination coefficient was 0.9987, the least chi-square was 1.959x10(-4), and the effective diffusivity was 2.33742x10(-1)0m(2)/s. The diffusion approach is the best among the eight models.Öğe FREEZE-DRYING KINETICS AND DIFFUSION MODELING OF SAFFRON (CROCUS SATIVUS L.)(Wiley-Blackwell, 2015) Acar, Bahadir; Sadikoglu, Hasan; Doymaz, IbrahimThe freeze drying is a suitable dehydration process for saffron that contains heat-sensitive volatile and aroma-yielding compounds such as crocin (act as a coloring agent), picrocrocin (responsible for the taste) and safranal (volatile oil that gives characteristic odor and aroma). The heat-sensitive volatile and aroma-yielding compounds of saffron can be more preserved using freeze drying in comparison with other conventional drying methods. In this study the freeze-drying characteristics of saffron was determined experimentally. The drying kinetics data were fitted to 10 different empirical diffusion drying models from literature to find the best model that represents the weight loss of saffron during the freeze drying. Among the models tested in this study, the Page model was found to be the best model in representing the drying kinetics of saffron during the freeze drying. Effective diffusivity found as 1.62x10(-11)m(2)/s. Practical ApplicationsSaffron, which has been intensively used for flavoring and coloring foods, dying textile and medical purposes since ancient times, is the most precious and expensive agricultural product in the world. Freeze drying, which is both slow and expensive, is the method of separation for high market value products. It has been shown that freeze drying can be used for dehydration of saffron with minimum safranal (main aroma component) and crocin (coloring agent) loss. High cost of freeze drying of saffron can be compensated by minimum loss of safranal and crocin contents in the final product. It is crucial to know the drying kinetics of saffron to determine the drying time under certain conditions. In this work, the freeze-drying kinetics of saffron were studied and the best empirical model that represents the weight loss of saffron during the freeze drying and effective diffusivity were determined.Öğe Freeze-Drying of Persimmon (Diospyros Kaki) Slices Investigation of Drying Characteristics(Gazi Univ, 2023) Dagdeviren, Abdullah; Acar, Bahadir; Alhammadiy, Abdullatif; Roshanaei, Khandan; Coskun, Tuba; Inanc, Ozgur; Ozkaymak, MehmetThis study was performed to define the kinetic drying model and to define the effective diffusivity coefficient of the fruit, which is called Diospyros kaki in the literature, from the family of Ebonaceae known as the Persimmon in our country. In the study, blueberries by the weight of 100 g and with a thickness of 5 mm were placed in the drying device, and the data were processed by observing the weight loss every two hours after being subjected to the drying process for 14 hours. 8 different kinetic drying models were applied to the acquired data using the Matlab program. As a result of the application, the estimated standard errors (RMSE), chi-square (X-2), regression coefficients (R-2) were calculated, error analysis was performed, R-2, X-2, and RMSE values were found, as 0.019483, 5.062 x 10(-4) and 0.9558. According to these results, it was determined that the most suitable model is the Page model. Also, the effective diffusivity coefficients for Persimmon (Diospyros Kaki) were calculated as 1.79775 x 10(-10) m(2)/s.Öğe Investigation of Energy Generation at Test System Designed by Use of Concentrated Photo-Voltaic Panel And Thermoelectric Modules(Int Journal Renewable Energy Research, 2018) Acar, Bahadir; Bas, SahinSystems of concentrating solar energy (CPV) are photovoltaic systems that contain light-intensifying optical components. It is expected to increase performance of solar energy cell by improving sunlight intensity that falls on solar energy cell with these systems. A system of concentrating solar energy consists of a light-intensifying optical component, cell platform, also reciever, heat tank for thermal applications, main module body that consists these components as placed in approriate manner and sun tracking system. Each of these matters is still in need of research and development studies. In this study, concentrating solar system that is rarely prefered in practical use at area and thermoelectric generators were used together to develop a hybrid energy generating system. Thus, it has been researched the potential of energy generation as preferably less cost. Also, it has been determined that heat increase of water that is being used as cooling water can be evaluated in order to help thermal process and recovery as usable water due to potential of obtaining 30% of temperature increase from waste water. It has been found in study that concentrated solar energy cells can generate 15% more voltage and 60% more current than standard usage and three thermoelectric modules connected as series can generate average of 5,19 V of voltage and 0,47 A of current especially integrated to system on summers. On the other hand, it is predicted that this system will provide a light for similar studies because the system has no carbon emissions and sufficient energy efficiency.Öğe Kinetic Model And Effective Diffusivity Of Frozen-Dryed European Blueberry (Vaccinium Myrtillus)(Gazi Univ, 2022) Ayriksa, Mutlucan; Acar, Bahadir; Dagdeviren, Abdullah; Roshanaei, Khandan; Coskun, Tuba; Ongun, Goknur K.; Ozkaymak, MehmetIn current study, the freeze-drying (FD) method has been investigated. This method is the healthiest drying method that used in recent years by extending the shelf life of the products and preserving the beneficial flavors in its content. Antioxidant, antimicrobial, antidiabetic, anti-inflammatory, antiseptic, etc., are the most emphasized role among the berries. Thus, blueberry is one of the great aspects to be a case for drying. Blueberry (Vaccinium Myrtillus), which is an opulent source of many phenolic compounds with known properties, has been determined. In the study, blueberries by the weight of 100 g and with a thickness of 5 mm were placed in the drying device, and the data were processed by observing the weight loss every two hours after being subjected to the drying process for 14 hours. 8 different kinetic drying models were applied to the acquired data using the Matlab program. As a result of the application, the estimated standard errors (RMSE), chi-square (X-2), regression coefficients (R-2) were calculated, error analysis was performed, R-2, X-2, and RMSE values were found, as 1.4686 x 10(-2), 2.875 x 10(-4) and 9.978 x 10(-1). According to these results, it was determined that the most suitable model is the Page model. Also, the effective diffusivity coefficients for blueberries were calculated as 2.57665 x 10(-12) m(2)/s.Öğe Laminar Forced Convection of Various Nanofluids in Sudden Expansion Channels Under Constant Heat Flux: A CFD Study(Imperial College Press, 2019) Acar, BahadirIn the present work, forced convection heat transfer was investigated numerically for the fully developed fluid flow of incompressible viscous laminar flow under the constant wall heat flux in sudden expansion channels. Various fluids were used with different concentration of nanoparticle such as Al2O3, TiO2, ZnO, CuO, SiO2. These nanoparticles were dispersed with the range of 0.5-2% volume concentrations in pure water to form stable suspensions of nanofluids. The flow assumed to be uniform in the channel inlet and numerical computations were performed for the fully developed laminar flow conditions. Ansys Fluent 16.1 code, based on finite volume approach was used to calculate the governing continuity, momentum and energy equations. Effect of the Re numbers (100 <= Re <= 500), nanoparticle volume concentration (0.5%<= phi <= 2.0%) and nanofluid type on the flow and heat transfer characteristics such as convective heat transfer coefficient, Nu number, friction factor and pressure drop has been investigated. Al2O3/water nanofluid was found better when compared the other references working fluids by means of heat transfer enhancement.Öğe A New Hybrid System Design for Thermal Energy Storage(Springer, 2020) Ceylan, Ilhan; Ali, Ismail Hamad Guma; Ergun, Alper; Gurel, Ali Etem; Acar, Bahadir; Islam, NurselDue to some serious environmental problems like global warming and greenhouse effect, studies on solar energy systems are being conducted all over the world. The studies conducted in recent years are on hybrid designs in which solar energy systems can realize both electricity and heat production at the same time. In this way, both electrical energy and heat energy can be generated from the same system In this study, the design and analysis of a concentrated solar air collector with a heat storage unit were carried out.. In the solar air collector, heat energy was depot in paraffin wax, and the electrical energy which was stored in the battery using the PV (photovoltaic) modules in the system enabled the operation of the system fan. The experiments which aimed at determining system performance were carried out in winter when the ambient temperature was low. The experiments were performed with or without a heat storage unit, and a comparative analysis was made. It was found that the temperature of the air released from the collector ranged from 15 degrees C to 40 degrees C when the exterior temperature was -5 degrees C. The average efficiency of the concentrated system without the heat storage unit was calculated as 67%. The average efficiency of the concentrated system with the heat storage unit was calculated as 96%.
